(1) Field of the Invention
This invention relates to an object recognition system, and more particularly to a system in which, as in a sonar, the features of an object such as size and shape are grasped from a reflected wave or echo from the object so as to recognize the object.
(2) Description of the Prior Art
In conventional object recognition systems such as sonar, it has been mainly aimed at to detect an object, i.e., to know the presence of an object. Since the recognition of an object has mostly relied on hearing by a sonar operator, etc., a satisfactory recognition performance has not been attained, and many attempts for recognizing the feature of object automatically have not been made.
Mentioned as a reason for the unsatisfactory recognition performance is that conventional signal processing systems, etc., are deemed to be suitable chiefly for the detection of a signal and that careful consideration is not always given to the adaptation for the recognition of an object.
Simultaneously, complicated and diverse properties ascribable to, for example, the multiple reflections of an object, i.e., reflections at many points on an object are considered a major reason for the difficult recognition of an object.